[Elecraft] Change to Elecraft Keying Mod

[Guy Olinger, K2AV]

Well, it is correct "enough", because I said SLOPING, which it does
do.

Since the curve is in db, it has to be converted to absolute values
for the addition.  Divide the channel up into narrow slices to get
voltages to add up for integration.

The green curve slopes down from 250 to 750 Hz across the channel. If
from the 250 side you are adding 1 volt slices, from the 750 side you
are adding something like 0.02 volt slices. That rise on the left side
of the curve is more than enough to overwhelm the 10 db improvement at
650-750. This will be particularly true if the person is on the high
side adjacent listening LSB or down listening USB, since the power of
the clicks will be at a higher audio tone in his receiver.

To approximate this effect, which varies widely, you would need to add
an extra 6 db slope to WORSEN any sloped channel spread. This occurs
because our eardrums are only a 1/4 inch across and respond more
easily to higher frequencies. (Also an operating trick to try next to
a clicky station.)

For the bloke trying to listen at 250-750 Hz, your mod has made things
worse. For the one listening at 750-1250, your mod has made it quite
better. But since the fellow at 250-750 was the most affected to start
with,

HOWEVER, given how much you have accomplished thus far, you can have
your cake and eat it too. Keep working on it.

But no doubt about it, so far Wayne has you in the 250-750 range.

73, Guy


----- Original Message ----- 
From: "John, KI6WX" <ki6wx@pacbell.net>
To: "Guy Olinger, K2AV" <olinger@bellsouth.net>;
<elecraft@mailman.qth.net>
Sent: Monday, March 29, 2004 1:40 AM
Subject: Re: [Elecraft] Change to Elecraft Keying Mod


>
> Your method of computing the comparison numbers is mathematically
incorrect.
> You can not take a peak value at one point in a communications
channel and
> do the comparison at that point.  You need to integrate both
measurements
> across the entire bandwidth of the communications channel to compare
the
> relative noise generated by each keying waveform.